1. Field of the Invention
The present invention relates to stabilized synthetic polymer compositions containing as a stabilizer a specified benzotriazole compound having a preventive effect on synthetic polymers against decomposition or deterioration.
2. Description of the Prior Art
Synthetic polymers such as synthetic resins and rubbers are liable to undergo decomposition or deterioration by the action of heat, light or enzymes associated with the supply of energy from the outside. If heavy metals such as Mn, Co, Cu, Fe and Pb, whether in the form of an ion or a complex in the reaction system, the decomposition or deterioration could be substantially accelerated owing to their catalytic action.
Though undesired, synthetic resins or rubbers are frequently used in the state where heavy metals are contained as impurities in them or placed in contact with them.
For the prevention of such decomposition or deterioration, improvements have been made by the use of additives such as antioxidants, stabilizers toward light but to insufficient degrees, with an extreme case of being ineffect. For example, poly-.alpha.-olefin resins, particularly polypropylene resin, recently having become increasingly used in virtue of their characteristics, to considerably prevent oxidative deterioration by the combined use of various antioxidants. The use of such a coating on copper wires or electrical insulators, or for printed wiring results in such deterioration or decrease in machinery strength, as to become practicaly unusable in several months.
In addition, electroplating on plastics has become more and more widespread. For instance, electroplating of an polypropylene object with copper consists essentially of making a first coating layer of chemical nickel directly over the object and then overlapping copper on the the first coating layer in order to prevent deterioration due to the contact between polypropylene and copper.
The use of colorants which can impart color to polypopylene or others, particularly pigments containing heavy metals, such as phthalocyanine blue, is observed to accelerate deterioration of plastics by the action of the heavy metals, which being reflected in the limited use of colorants.
For the purpose of preventing synthetic polymers from undergoing deterioration by the action of the aforenoted heavy metals, various heavy metal-inactivating agents have been proposed. For example, benzotriazole for olefin polymers is disclosed in Japanese Published Patent No. 19554/1966, N-salicylidene-N'-salicylhydrazine compounds for organic materials in the same No. 12293/1965, oxalic acid bis(salicylidene hydrazide) compounds for olefin polymers in the same No. 15466/1974, diacylhydrazide compounds for olefin polymers in Japanese Laid-open Patent No. 7088/1971, alkylhydroxyphenylalkanoylhydrazine compounds for organic materials in 27624/1972 in Japanese Published Patent No. 27624/1972, thiodialkanoic acid bis(hydrazide) compounds for olefin polymers in the same No. 23415/1970, and diacylbis(phenoxyalkylhydrazide) compounds for high molecules in the same No. 43537/1979. These compounds however produce only effects on synthetic compounds which are still far from fulfilling thoroughly the desired results.